Trubion Pharmaceuticals, Inc. (Nasdaq: TRBN) announced the acceptance of three data presentations on its proprietary product candidate, TRU-016, that will be given at the 2009 American Society of Clinical Oncology (ASCO) Annual Meeting May 29 through June 2 in Orlando, Fla. The presentations will include positive data from a Phase 1 clinical trial of TRU-016 for the treatment of chronic lymphocytic leukemia (CLL), a preclinical study demonstrating the additive or synergistic effects of TRU-016 in combination with other therapeutic drugs for the treatment of non-Hodgkin's lymphoma (NHL), and a preclinical study evaluating the effect of TRU-016 on direct apoptosis in CLL cells.

Abstract 3017 (May 31, 2009): A Phase 1 Trial of TRU-016, An Anti-CD37 Small Modular ImmunoPharmaceutical (SMIP(TM)), in Relapsed and Refractory CLL -- Early Promising Clinical Activity

As of the abstract submission, 10 patients enrolled in the Phase 1 trial had received intravenous doses ranging from 0.03 mg/kg to 3.0 mg/kg of TRU-016. Initial data from the study demonstrates the safety and early signs of efficacy of TRU-016 as shown by a reduction in tumor lymphocyte blood counts, reduction in lymph node and spleen size, and/or an improvement in hematopoiesis, or the production of red blood cells and platelets.

Eight of the 10 patients had high-risk genomic features and no dose-limiting toxicities or serious adverse events had occurred. Mild (grade 1-2) infusion toxicity was observed in three patients. Beginning with the 0.3 mg/kg dose, all eight patients demonstrated evidence of biological activity including high-risk patients. Two patients had partial clearing of leukemia cutis, and the other six had 27% to 94% reduction in peripheral lymphocyte count. One patient had an increase in hemoglobin of 40% and a reduction in lymph nodes of 36%. Two patients had a significant increase in platelet count.

TRU-016 is a humanized SMIP protein therapeutic that targets the CD37 antigen and has shown potent anti-tumor activity in pre-clinical studies. Trubion initiated a Phase 1/2 clinical trial of TRU-016 in March 2008. The open-label clinical trial has two components: a Phase 1 dose escalation study designed to evaluate the safety, tolerability and pharmacokinetics of TRU-016, and a Phase 2 expansion cohort designed to further evaluate safety and estimate clinical activity of TRU-016 in patients with previously treated CLL or small lymphocytic lymphoma (SLL).

Abstract 8571 (May 30, 2009): Evaluation of the Effect of TRU-016 in Combination With Other Therapeutic Drugs in Models of Non-Hodgkin's Lymphoma

In addition, Trubion will also present at the 2009 ASCO Annual Meeting preclinical data evaluating TRU-016 interactions with the established therapeutics rituximab, doxorubicin, rapamycin, and bendamustine. Drugs were tested alone or in combination with TRU-016 for anti-proliferative effects on cell lines in vitro and on tumors in vivo.

Combination index analyses revealed that TRU-016 is synergistic with rituximab, bendamustine, or rapamycin and additive with doxorubicin in killing NHL cells in vitro. In vivo results show that treatment with the combination of TRU-016 and bendamustine resulted in greater efficacy compared to the efficacy attained with the individual drugs. These studies demonstrate that TRU-016 combined with rituximab, rapamycin, or bendamustine increases cell killing of NHL cells. Furthermore, the combination of TRU-016 and bendamustine displayed greater in vivo anti-tumor activity than either agent alone against a follicular lymphoma tumor model.

Abstract 3035 (May 30, 2009): Effect of CD37 Small Modular ImmunoPharmaceutical (SMIP) on direct apoptosis in chronic lymphocytic leukemia cells via transcriptional up-regulation of the BH3 family member BIM

Given the superior in vitro apoptosis observed with TRU-016 treatment and early clinical activity observed in highly refractory CLL patients, preclinical studies were performed on CLL cells to determine the mechanism(s) of direct TRU-016 mediated apoptosis. These studies demonstrate TRU-016-mediated apoptosis in CLL cells occurs via a distinct mechanism of apoptosis compared with many other therapeutic agents utilized for the treatment of CLL.

"The data to be presented at ASCO expands our pre-clinical experience and reinforces our belief that TRU-016 has the potential to improve treatment options for patients with B-cell malignancies like CLL and NHL," said Peter Thompson, M.D., FACP, president, CEO and chairman of Trubion. "Patients with relapsed or refractory disease often show steadily diminished response to current therapies. The preliminary data from the Phase 1 study are very encouraging as TRU-016 shows the potential to produce promising single-agent clinical activity in patients whose disease is recurring or patients who are no longer responding to prior treatments. The demonstrations that TRU-016 works through a novel and powerful mechanism of action, synergizes in vitro with a broad array of small molecule therapeutics, and shows significant in vivo efficacy in combination with bendamustine add to our enthusiasm for the continued development of this first-in-class product candidate, both as a single agent and as a component of combination regimens."

About Trubion

Trubion is a biopharmaceutical company that is creating a pipeline of novel protein therapeutic product candidates to treat autoimmune and inflammatory diseases and cancer. The Company's mission is to develop a variety of first-in-class and best-in-class product candidates, customized for optimal safety, efficacy and convenience that it believes may offer improved patient experiences. Trubion's current product candidates are novel single-chain protein, or SMIP(TM), therapeutics, and are designed using its custom drug assembly technology. Trubion's product pipeline includes CD20-directed SMIP therapeutics such as TRU-015 and SBI-087 for autoimmune and inflammatory diseases, developed under the Company's Wyeth collaboration. Trubion's product pipeline also includes Trubion's proprietary product candidate, TRU-016, a novel CD37-targeted therapy for the treatment of B-cell malignancies that is currently in Phase 1/2 clinical evaluation. In addition to Trubion's current clinical stage product pipeline, the Company is also developing additional product candidates that build on its product development experience.

Forward-Looking Statements

Certain statements in this release may constitute "forward-looking statements" within the meaning of Section 21E of the Securities Exchange Act of 1934 and Section 27A of the Securities Act of 1933. These statements include, but are not limited to, those related to the Company's future clinical development programs and the timing thereof, the Company's future regulatory filings and the timing and outcome thereof. These statements are based on current expectations and assumptions regarding future events and business performance and involve certain risks and uncertainties that could cause actual results to differ materially. These risks include, but are not limited to, risks associated with the clinical advancement of TRU-016, the Company's Wyeth collaboration, including Wyeth's control over development timelines, the risks that the Company is unable to advance its clinical development programs and regulatory applications and action at the rate it expects, and such other risks as identified in the Company's quarterly report on Form 10-Q for the period ended March 31, 2009, and from time to time in other reports filed by Trubion with the U.S. Securities and Exchange Commission.

Source: Trubion Pharmaceuticals, Inc